JP7024636B2 - Manufacturing method of sputtering target - Google Patents

Description

The present invention relates to a method for manufacturing a sputtering target used for forming an oxide film containing Zn, Sn and O as main components.

The above-mentioned oxide film containing Zn, Sn, and O as main components has excellent transmittance in the visible light region and also has excellent infrared reflection characteristics. Therefore, a heat shield film such as a window glass, an infrared filter, etc. Is used for.
Here, the above-mentioned oxide film is formed by, for example, as shown in Patent Document 1-5 below, by performing sputtering using a sputtering target made of an oxide. As the above-mentioned sputtering target, for example, one having a flat plate shape or a cylindrical shape is provided.

Patent Document 1 proposes a sputtering target composed of an oxide sintered body mainly composed of a tin-zinc composite oxide phase and a metallic tin phase. In Patent Document 1, tin oxide (SnO) and zinc oxide (ZnO) are used as raw materials, and tin oxide (SnO) is reduced to form a metallic tin phase.
Further, Patent Documents 2 and 3 propose a sputtering target composed of an oxide sintered body of Zn and Sn. In these Patent Documents 2 and 3, zinc oxide (ZnO) and stannous oxide (SnO ₂ ) are used as raw materials.

Further, Patent Document 4 proposes a sputtering target which is an oxide sintered body substantially composed of tin, zinc and oxygen and is mainly composed of a tin-zinc composite oxide phase and a tin oxide phase. There is. In this Patent Document 4, zinc oxide (ZnO) and stannous oxide (SnO ₂ ) are used as raw materials.
Further, Patent Document 5 proposes a sputtering target in which at least one metal oxide of zinc oxide and tin oxide and a metal powder are sintered.

Japanese Unexamined Patent Publication No. 2013-177260 Japanese Unexamined Patent Publication No. 2010-037161 Japanese Unexamined Patent Publication No. 2010-031364 Japanese Unexamined Patent Publication No. 2007-314364 Japanese Unexamined Patent Publication No. 2014-167162

By the way, in the sputtering target described in Patent Document 1, the relative density is about 91.1 to 93.6%, and the one having a sufficiently high density has not been obtained.
Further, the tin-zinc composite oxide phase and the metallic tin phase are the main phases, and the specific resistance value differs greatly between the tin-zinc composite oxide phase region and the metallic tin phase region on the target sputter surface, so that sputtering occurs. There was a risk that the number of abnormal discharges would increase. Furthermore, since the coefficient of thermal expansion of the tin-zinc composite oxide phase and the metallic tin phase are significantly different, when the temperature rises during sputtering, the surface of the target is cracked due to thermal expansion, and stable sputtering is performed. There was a risk that it could not be done.

Further, in the sputtering targets described in Patent Documents 2 and 3, since the resistance of the target itself is very high and DC (direct current) sputtering is difficult, it is premised that RF (radio frequency) sputtering is performed. In this RF (radio frequency) sputtering, there are problems that the film forming speed is slow and the productivity is lowered.
Further, although it is described that DC sputtering is possible in the sputtering target described in Patent Document 4, the specific resistance value thereof is relatively high, for example, several tens of Ω · cm, so that DC (direct current) sputtering is stable. It was difficult to carry out.

Further, in the sputtering target described in Patent Document 5, since the metal powder and the oxide are sintered, the metal powder is dispersed and exists as a metal phase, so that the conductivity of the target is improved. It is stated that DC sputtering is possible. However, in Patent Document 5, since the metal powder and the oxide are simply sintered, if the sintering temperature is set to be equal to or higher than the melting point of the metal powder, the metal powder will melt out, so that the sintering temperature is raised. It was not possible to set it, and it was difficult to sufficiently improve the density. Further, since the metal phase is composed of the metal powder used at the time of sintering, the size of the metal phase depends on the particle size of the metal powder, so that the fine metal phase can be separated without segregation. It was difficult to disperse evenly.
As described above, in the sputtering target described in Patent Document 5, since many voids are present and the metal phase is non-uniformly present, the number of abnormal discharges during sputtering may increase. rice field. In addition, cracks may occur during sputtering, and stable sputtering may not be possible.

The present invention has been made in view of the above-mentioned circumstances, and is a method for manufacturing a sputtering target capable of suppressing the occurrence of abnormal discharge, having a sufficiently low resistivity value, and stably performing DC sputtering. The purpose is to provide.

As a result of diligent studies by the present inventors in order to solve the above problems, in a sputtering target having a tin oxide phase and a tin-zinc composite oxide phase as the main phases and having a metallic tin phase uniformly dispersed without segregation. Can suppress the occurrence of abnormal discharge during sputtering, and can improve the relative density by dispersing the metallic tin phase so as to fill the gaps between the particles of the oxide phases serving as the parent phase. I got the knowledge of.

The present invention has been made based on the above findings, and the method for manufacturing a sputtering target of the present invention contains Zn, Sn and O as main components, and Zn / (Zn + Sn) is an atomic ratio of Zn and Sn. A method for producing a sputtering target containing a tin oxide phase and a tin-zinc composite oxide phase as main phases and having a metallic tin phase, which is contained so as to be in the range of 0.1 or more and 0.6 or less. A raw material powder forming step of mixing zinc oxide (ZnO) powder, tin oxide (SnO ₂ ) powder, and stannous oxide (SnO) powder to obtain a raw material powder, and heating while pressurizing the obtained raw material powder. It has a sintering step of obtaining a sintered body, and is characterized in that in the sintering step, stannous oxide (SnO) is reacted to generate the metallic tin phase. ..

According to the method for producing a sputtering target of the present invention, a raw material powder forming step of mixing zinc oxide (ZnO) powder, stannic oxide (SnO ₂ ) powder and stannous oxide (SnO) powder to obtain a raw material powder. Since the obtained raw material powder has a sintering step of heating the obtained raw material powder while pressurizing and sintering to obtain a sintered body, the zinc oxide uniformly mixed in the sintering step ( SnO) The powder reacts according to the following reaction formula to form a metallic tin phase.
2SnO → Sn + SnO ₂
Therefore, the tin oxide phase and the tin-zinc composite oxide phase are the main phases, and the metallic tin phase is uniformly dispersed without segregation, so that the occurrence of abnormal discharge can be suppressed and the resistivity value is sufficient. It is possible to manufacture a sputtering target capable of DC sputtering in a low and stable manner.

Here, in the method for producing a sputtering target of the present invention, the content of tin oxide (SnO) powder in the raw material powder is within the range of 1 mol% or more and 20 mol% or less in the raw material powder forming step. Is preferable.
In this case, since the content of the stannous oxide (SnO) powder in the raw material powder is 1 mol% or more, the ratio of the stannous oxide (SnO) powder is secured, and the metallic tin phase is obtained by the above reaction formula. Can be reliably generated. On the other hand, since the content of the stannous oxide (SnO) powder in the raw material powder is 20 mol% or less, the metallic tin phase is not formed more than necessary, and the leaching of the metal is surely suppressed. be able to.

Further, in the method for producing a sputtering target of the present invention, the average particle size of the tin oxide (SnO ₂ ) powder is 30 μm or less, and the average particle size of the tin oxide (SnO) powder is 30 μm or less. It is preferable to have.
In this case, since the average particle size of the stannous oxide (SnO) powder is 30 μm or less, it is possible to form a fine metallic tin phase. Further, since the average particle size of the tin oxide (SnO ₂ ) powder is 30 μm or less, the tin oxide (SnO) powder is surrounded to suppress the aggregation of the metallic tin phase and the dissolution of the metal. Can be done.

Further, in the method for manufacturing a sputtering target of the present invention, in the sintering step, the sintering temperature is in the range of 950 ° C. or higher and 1200 ° C. or lower in a non-oxidizing atmosphere, and the holding time at the sintering temperature is 180 minutes. It is preferable that the pressurizing pressure is 40 MPa or less within the range of 300 minutes or less.
In this case, since the conditions of the sintering step are defined as described above, it is possible to reliably form a sintered body having a high relative density. In addition, the above-mentioned reaction formula makes it possible to reliably generate a metallic tin phase.

According to the present invention, it is possible to provide a method for manufacturing a sputtering target capable of suppressing the occurrence of abnormal discharge and stably performing DC sputtering with a sufficiently low resistivity value.

6 is a microstructure observation photograph (EPMA image) of a sputtering target manufactured by the method for manufacturing a sputtering target according to the embodiment of the present invention. It is a flow figure which shows the manufacturing method of the sputtering target which is an embodiment of this invention. It is a figure which shows the result of having confirmed the presence or absence of a metallic tin phase by XRD analysis in an Example.

Hereinafter, a method for manufacturing a sputtering target according to an embodiment of the present invention will be described with reference to the attached drawings.

First, a sputtering target manufactured by the method for manufacturing a sputtering target according to the present embodiment will be described.
This sputtering target contains Zn, Sn, and O as main components, and contains Zn and Sn so that the atomic ratio of Zn / (Zn + Sn) is in the range of 0.1 or more and 0.6 or less.
Further, the sputtering target of the present embodiment has a tin oxide phase and a tin-zinc composite oxide phase as main phases and a metallic tin phase. In this embodiment, as a result of X-ray diffraction analysis, it was confirmed that the tin oxide phase is the stannic oxide phase (SnO ₂ phase) and the tin-zinc composite oxide phase is the Zn ₂ SnO ₄ phase. ing.
Here, in the X-ray diffraction analysis, when the maximum peak corresponding to the substance composed of Zn, Sn, and O is larger than the peak corresponding to other substances, it is assumed that Zn, Sn, and O are the main components. to decide.

As shown in FIG. 1, the sputtering target of the present embodiment has a structure in which the metallic tin phase is dispersed in the oxide phase (tin oxide phase and tin-zinc composite oxide phase) which is the parent phase, and is described above. The metallic tin phase is uniformly dispersed without segregation. Here, in FIG. 1, the white portion is a metallic tin phase, the light gray portion is a tin oxide phase (SnO ₂ ), and the dark gray portion is a tin-zinc composite oxide phase (Zn ₂ SnO ₄ ).

Further, in the sputtering target of the present embodiment, the relative density is 95% or more.
Further, in the sputtering target of the present embodiment, the specific resistance value is set to 1 Ω · cm or less.

Hereinafter, the reasons for defining the atomic ratio, relative density, and resistivity value in the sputtering target of the present embodiment as described above will be described.

(Atomic ratio Zn / (Zn + Sn): 0.1 or more and 0.6 or less)
In the sputtering target of the present embodiment, an oxide film to be a heat shield film is formed, and it is necessary to satisfy the transmittance and infrared reflection characteristics in the visible light region.
Here, by containing Zn and Sn so that Zn / (Zn + Sn) is in the range of 0.1 or more and 0.6 or less in atomic ratio, an oxide film satisfying the above-mentioned various characteristics is formed. be able to.
In order to reliably form an oxide film having excellent various characteristics, the lower limit of the atomic ratio Zn / (Zn + Sn) is preferably 0.2 or more, and more preferably 0.25 or more. .. Further, the upper limit of the atomic ratio Zn / (Zn + Sn) is preferably 0.5 or less, and more preferably 0.4 or less.

(Relative density: 95% or more)
Relative density is the measured density divided by the theoretical density. In the present embodiment, the theoretical density is calculated by the following formula, assuming that the content of the metallic tin phase is calculated by the Rietveld method and the remaining Sn and Zn are SnO ₂ and ZnO, respectively.
Theoretical density = 100 / {(Wa / Da) + (Wb / Db) + (Wc / Dc)}
Wa: SnO ₂ content (% by mass)
Da: Theoretical density of SnO ₂ (6.95 g / cm ³ )
Wb: ZnO content (% by mass)
Db: Theoretical density of ZnO (5.61 g / cm ³ )
Wc: Metal Sn content (% by mass)
Dc: Theoretical density of metal Sn (7.30 g / cm ³ )

If the relative density of the sputtering target calculated by the above formula is less than 95%, a large number of voids will be present, and there is a possibility that abnormal discharge is likely to occur during sputtering. In addition, the sputtering target may be cracked after sputtering. Therefore, in this embodiment, the relative density is specified to be 95% or more. Here, the density of the sputtering target may exceed the theoretical density calculated by the above formula due to the reaction of the raw material powder or the like, in which case the relative density exceeds 100%.
In order to further suppress the occurrence of abnormal discharge and cracking during sputtering, the relative density of the sputtering target is preferably 96% or more, and more preferably 98% or more. Further, although the upper limit of the relative density is not particularly limited, it is difficult to produce a sintered body having a relative density of 105% or more.

(Specific resistance value: 1Ω ・ cm or less)
In order to stably perform DC sputtering, in the sputtering target of the present embodiment, the specific resistance value is preferably 1 Ω · cm or less, and more preferably 0.1 Ω · cm or less. The lower limit of the specific resistance value is not particularly limited, but is, for example, 0.001 Ω · cm or more.

Next, the method for manufacturing the sputtering target according to the present embodiment will be described with reference to the flow chart of FIG.

(Raw material powder forming step S01)
First, zinc oxide (ZnO) powder, stannous oxide (SnO ₂ ) powder, and stannous oxide (SnO) powder are prepared and mixed to obtain a raw material powder. At this time, zinc oxide (ZnO) powder and stannous tin oxide (SnO ₂ ) powder are used so that Zn / (Zn + Sn) is in the range of 0.1 or more and 0.6 or less in terms of atomic ratio of Zn and Sn. Weigh with tin oxide (SnO) powder.
The weighed zinc oxide (ZnO) powder, stannous oxide (SnO ₂ ) powder, and stannous oxide (SnO) powder are mixed using a mixing device such as a ball mill. When mixing these powders, it is preferable to carry out the mixing in a non-oxidizing atmosphere such as an inert gas atmosphere.

Here, in the method for manufacturing a sputtering target according to the present embodiment, tin oxide (SnO) powder is used as the raw material powder, and in the sintering step S02 described later, the stannous oxide (SnO) is described below. A metallic tin phase is formed by the reaction shown in the reaction formula of.
2SnO → Sn + SnO ₂

Here, in the present embodiment, the content of tin oxide (SnO) powder in the raw material powder is preferably in the range of 1 mol% or more and 20 mol% or less.
When the content of the stannous oxide (SnO) powder in the raw material powder is 1 mol% or more, the metallic tin phase can be reliably produced. On the other hand, when the content of the stannous oxide (SnO) powder in the raw material powder is 20 mol% or less, the metallic tin phase is not generated more than necessary, and it is possible to surely suppress the leaching of the metal.
The lower limit of the content of tin oxide (SnO) powder in the raw material powder is more preferably 3 mol% or more, and further preferably 5 mol% or more. On the other hand, the upper limit of the content of tin oxide (SnO) powder in the raw material powder is more preferably 18 mol% or less, more preferably 15 mol% or less.

In order to form a fine metallic tin phase, the average particle size of the stannous oxide (SnO) powder is preferably 30 μm or less, more preferably 25 μm or less. The lower limit of the average particle size of the stannous oxide (SnO) powder is not particularly limited, but is preferably 0.1 μm or more, for example.
Further, in order to surround the stannous oxide (SnO) powder and suppress the leaching of the metal, the average particle size of the stannous oxide (SnO ₂ ) powder is preferably 30 μm or less, preferably 25 μm or less. Is even more preferable. The lower limit of the average particle size of the tin oxide (SnO ₂ ) powder is not particularly limited, but is preferably 0.1 μm or more, for example.
Further, the average particle size of the zinc oxide (ZnO) powder is preferably in the range of 0.1 μm or more and 100 μm or less.

(Sintering step S02)
Next, the raw material powder obtained by mixing is filled in a molding die, heated while being pressurized, and sintered to obtain a sintered body.
In this sintering step S02, the tin oxide (SnO) powder uniformly mixed reacts as in the above reaction formula, so that the metallic tin phase is uniformly formed without segregation. Become. That is, in the present embodiment, the metallic tin phase is formed by reaction sintering.

Here, in the present embodiment, the sintering temperature in the sintering step S02 is in the range of 950 ° C. or higher and 1200 ° C. or lower, the holding time at the sintering temperature is in the range of 180 minutes or more and 300 minutes or less, and the pressurizing pressure is set. It is preferably 40 MPa or less. The atmosphere is preferably a non-oxidizing atmosphere, and in the present embodiment, a vacuum atmosphere of 20 Pa or less is used.

When the sintering temperature is 950 ° C. or higher, the density of the sintered body can be sufficiently improved. On the other hand, when the sintering temperature is 1200 ° C. or lower, it is possible to reliably suppress the leaching of the metal. The upper limit of the sintering temperature is more preferably 1100 ° C. or lower.

If the holding time at the sintering temperature is 180 minutes or more, the density of the sintered body can be sufficiently improved. On the other hand, if the holding time at the sintering temperature is 300 minutes or less, it is possible to reliably suppress the leaching of the metal. The lower limit of the holding time at the sintering temperature is more preferably 200 minutes or more. Further, it is more preferable that the upper limit of the holding time at the sintering temperature is 280 minutes or less.

Further, by setting the pressurizing pressure to 40 MPa or less, it is possible to surely suppress the leaching of the metal. The upper limit of the pressurizing pressure is more preferably 35 MPa or less. The lower limit of the pressurizing pressure may be 0, but by setting it to 20 MPa or more, it is possible to increase the density of the sintered body.
Further, by sintering in a non-oxidizing atmosphere, oxidation of metallic tin can be suppressed, and a metallic tin phase can be reliably formed.

(Machining process S03)
Next, the obtained sintered body is machined so as to have a predetermined size. As a result, the sputtering target according to the present embodiment is manufactured.

According to the method for producing a sputtering target according to the present embodiment having the above configuration, zinc oxide (ZnO) powder, stannic oxide (SnO ₂ ) powder, and stannous oxide (SnO) powder are mixed. Since it has a raw material powder forming step S01 for obtaining the raw material powder and a sintering step S02 for obtaining a sintered body by heating the obtained raw material powder while pressurizing it, the sintering step S02. In, the uniformly mixed stannous oxide (SnO) powder will form a metallic tin phase by the reaction shown in the above reaction formula.
Therefore, the tin oxide phase and the tin-zinc composite oxide phase are the main phases, and the metallic tin phase is uniformly dispersed without segregation, so that the occurrence of abnormal discharge can be suppressed and the resistivity value is sufficient. It is possible to manufacture a sputtering target capable of DC sputtering in a low and stable manner.

Further, in the present embodiment, in the raw material powder forming step S01, the content of the stannous oxide (SnO) powder in the raw material powder is 1 mol% or more, so that the ratio of the stannous oxide (SnO) powder is secured. The above-mentioned reaction formula makes it possible to reliably produce a metallic tin phase. On the other hand, since the content of tin oxide (SnO) powder in the raw material powder is 20 mol% or less, the metallic tin phase is not formed more than necessary, and the leaching of the metal is surely suppressed. Is possible.

Further, in the present embodiment, since the average particle size of the stannous oxide (SnO) powder is 30 μm or less in the raw material powder forming step S01, it is possible to form a fine metallic tin phase. Further, since the average particle size of the tin oxide (SnO ₂ ) powder is 30 μm or less, the tin oxide (SnO) powder is surrounded to suppress the aggregation of the metallic tin phase and the dissolution of the metal. Can be done.

Further, in the present embodiment, in the sintering step S02, the sintering temperature is within the range of 950 ° C. or higher and 1200 ° C. or lower, and the holding time at the sintering temperature is within the range of 180 minutes or longer and 300 minutes or lower in a non-oxidizing atmosphere. Since the pressurizing pressure is 40 MPa or less, it is possible to reliably form a sintered body having a high relative density. In addition, the above-mentioned reaction formula makes it possible to reliably generate a metallic tin phase.

The sputtering target manufactured by the method for manufacturing a sputtering target of the present embodiment has a tin oxide phase and a tin-zinc composite oxide phase as main phases and also has a metallic tin phase, so that an abnormal discharge occurs during sputtering. Can be suppressed. Further, the metallic tin phase is sufficiently filled between the oxide phases serving as the parent phase, and the relative density can be improved. Further, even when the temperature rises during sputtering, it is possible to suppress the occurrence of cracks on the target surface due to thermal expansion.

Further, in the sputtering target of the present embodiment, since the relative density is 95% or more, there are few voids, and it is possible to suppress the occurrence of abnormal discharge during sputtering. In addition, it is possible to suppress the occurrence of cracks during spattering.
Further, in the sputtering target of the present embodiment, Zn / (Zn + Sn) is contained so that the atomic ratio of Zn / (Zn + Sn) is in the range of 0.1 or more and 0.6 or less, so that the transmissivity and infrared rays are contained. It is possible to form an oxide film having excellent reflection characteristics.

Although the embodiments of the present invention have been described above, the present invention is not limited to this, and can be appropriately changed without departing from the technical idea of the invention.

The results of the confirmation experiment conducted to confirm the effectiveness of the present invention will be described below.

(Sputtering target)
As raw material powder, zinc oxide powder (ZnO powder: purity 99.9 mass% or more, average particle size 10.0 μm), stannic oxide powder (SnO ₂ powder: purity 99.99 mass% or more, average particle size 25 μm), oxidation First tin powder (SnO powder: purity 99.99 mass% or more, average particle size 25 μm) was prepared. Further, as raw material powders used in the comparative examples, metallic zinc powder (metal Zn powder: purity 99 mass% or more, average particle size 4.0 μm) and metallic tin powder (metal Sn powder: purity 99 mass% or more, average particle size 15). .0 μm) was prepared.

These raw materials were weighed so as to have the mol ratio shown in Table 1, and the weighed raw materials, zirconia balls (diameter: 5 mm) and a solvent three times as heavy as the raw materials were put into a polyethylene pot. Then, wet mixing was performed by a ball mill device for 16 hours. After mixing and drying, the zirconia balls and the mixed powder were separated by sieving.

The obtained mixed powder was charged into a carbon molding mold, and pressure-sintered at a vacuum atmosphere (7 Pa) at the sintering temperature, holding time, and pressure shown in Table 1 to perform sintering. I got a body.
The obtained sintered body was machined to produce a sputtering target (126 mm × 178 mm × 6 mm) for evaluation. Then, the following items were evaluated.

(Melting metal)
After sintering, the presence or absence of metal (Sn or Zn) leaching was visually observed. The evaluation results are shown in Table 2. If metal leaching was observed, the spatter test described later was not carried out.

(Composition of sputtering target)
A measurement sample was collected from the obtained sputtering target, and the collected measurement sample was crushed into a powder for measurement. Using this powder for measurement, measurement is performed by a powder X-ray diffractometer (D8 ADVANCE manufactured by Bruker AXS Co., Ltd.), and analysis is performed by the Rietveld method (analysis software: TOPAS (version5) manufactured by Bruker AXS Co., Ltd.). The composition of the sputtering target was calculated. The measurement results are shown in Table 2. The measurement conditions were as follows.
Radioactive source: Cu
Tube voltage: 40kV
Tube current: 40mA
Scanning range: 15-128 deg
Step width: 0.01deg

(Presence or absence of metallic tin phase)
A sample for measuring an X-ray diffraction pattern was taken from the obtained sputtering target, and X-ray diffraction analysis (XRD) was performed under the following conditions to confirm the presence or absence of a metallic tin phase. The measurement results are shown in Table 2. Further, an example of the measurement result is shown in FIG.
Equipment: Made by Rigaku Denki Co., Ltd. (RINT-UltimaIII)
Tube: Cu
Tube voltage: 40kV
Tube current: 40mA
Scanning range (2θ): 10 ° to 90 °
Slit size: divergence (DS) 2/3 degree, scattering (SS) 2/3 degree, light receiving (RS) 0.8 mm
Measurement step width: 0.04 degrees at 2θ Scan speed: 4 degrees per minute Sample table rotation speed: 30 rpm

(Relative density)
The "theoretical density" was calculated by the method described in the column of the embodiment. Further, the value obtained by dividing the weight of the obtained sputtering target by the volume obtained from the dimensions was defined as the "measurement density".
Using this theoretical density and the measured density of the obtained sputtering target, the theoretical density ratio was calculated by the following formula. The measurement results are shown in Table 2.
Relative density (%) = (measured density) / (theoretical density) x 100

(Specific resistance value)
The resistivity value of the sputtering target was measured by a resistance measuring device. As a resistance measuring device, a low resistivity meter (Loresta-GP) manufactured by Mitsubishi Chemical Corporation was used, and the measurement was performed by the four-probe method. The temperature at the time of measurement was 23 ± 5 ° C., and the humidity was 50 ± 20%. The measurement results are shown in Table 2.

In Comparative Example 1 in which zinc oxide (ZnO) powder and stannous tin oxide (SnO ₂ ) powder were used as raw materials, no metallic tin phase was confirmed. Then, the specific resistance value was high, and DC sputtering could not be performed.
In Comparative Example 2 in which zinc oxide (ZnO) powder and stannous oxide (SnO) powder were used as raw materials, a metallic tin phase was formed, but leaching of the metal was confirmed. In addition, the relative density was as low as less than 95%.

In Comparative Example 3 in which zinc oxide (ZnO) powder, stannous tin oxide (SnO ₂ ) powder, and metallic zinc powder were used as raw materials and sintered at 400 ° C., no metallic tin phase was confirmed. In addition, it was confirmed that the metal had melted out. Furthermore, the relative density was as low as less than 95%.
In Comparative Example 4 in which zinc oxide (ZnO) powder, stannic oxide (SnO ₂ ) powder, and metallic zinc powder were used as raw materials and sintered at 950 ° C., a metallic tin phase was formed, but the metal was melted out. Was confirmed. In addition, the relative density was as low as less than 95%.

In Comparative Example 5 in which zinc oxide (ZnO) powder, stannous tin oxide (SnO ₂ ) powder, and metallic tin powder were used as raw materials and sintered at 950 ° C., a metallic tin phase was formed, but the metal was melted out. Was confirmed. In addition, the relative density was as low as less than 95%.

On the other hand, in Example 1-5 of the present invention using zinc oxide (ZnO) powder, stannous oxide (SnO ₂ ) powder and stannous oxide (SnO) powder as raw materials, the structure after sintering is used. A metallic tin phase was formed inside. In addition, the relative density was as high as 95% or more. Further, the specific resistance value was low, and DC sputtering could be stably performed.

As described above, according to the example of the present invention, it has been confirmed that it is possible to manufacture a sputtering target capable of suppressing the occurrence of abnormal discharge, having a low resistivity value, and stably performing DC sputtering. ..

Claims (4)

The main components are Zn, Sn and O, and Zn / (Zn + Sn) is contained so that the atomic ratio of Zn / (Zn + Sn) is in the range of 0.1 or more and 0.6 or less, and the tin oxide phase and the tin-zinc composite oxide are contained. It is a method for manufacturing a sputtering target having a phase as a main phase and a metallic tin phase.
A raw material powder forming step of mixing zinc oxide (ZnO) powder, stannic oxide (SnO ₂ ) powder, and stannous oxide (SnO) powder to obtain a raw material powder, and heating while pressurizing the obtained raw material powder. It has a sintering process to obtain a sintered body by sintering.
A method for producing a sputtering target, which comprises reacting stannous oxide (SnO) to form the metallic tin phase in the sintering step. The sputtering target according to claim 1, wherein in the raw material powder forming step, the content of tin oxide (SnO) powder in the raw material powder is in the range of 1 mol% or more and 20 mol% or less. Production method. ₁ . The method for manufacturing a sputtering target according to claim 2. In the sintering step, in a non-oxidizing atmosphere, the sintering temperature is in the range of 950 ° C. or higher and 1200 ° C. or lower, the holding time at the sintering temperature is in the range of 180 minutes or more and 300 minutes or less, and the pressurizing pressure is 40 MPa. The method for manufacturing a sputtering target according to any one of claims 1 to 3, wherein the method is as follows.

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